A drug is administered every 6 hours in dose of 6 mg. The drug is neutralized at an exponential rate with decay rate constant k = 0.4. Not all the drug is neutralized before the next dose is administered. Let . A(t): denote the amount of drug in the patient's system at time t hours, . Bn: denote the amount of drug in the patient at the beginning of the n+1 dosage interval, and . Rn: denote the residual amount of the drug left in the patent at the end of the nth dosage interval. Note: The general form of the Exponential decay Model is A(t) = Aoe-ki where: . Ao: denote the initial amount presented at time t = 0. . k: denote the decay rate (unit: 1/time) . A(t): denote the amount left at time t The formula for the function A(t) over the second dose periods is: O a) A(t) = 6e-0.4t Ob) A(1) = 6e-1.20-0.4(1-6) O d A(1) = (6+ 6e-2:4)e-0.4(1-6) O d) A(1) = (6+ 6e-1.6)e-0.4(1-6) O e) A(1) = (6+ 6e-1.6)e-0.4(1-4)